处在亚洲夏季风区域的青藏高原夏季上对流层和下平流层（UT-LS，约13-18 km）存在一个“亚洲对流层顶气溶胶层（ATAL）”。 模式和卫星观测推测ATAL与水汽输送、气溶胶前体物低温的气-粒转化、高空卷云生消及辐射强迫等有密切联系。ATAL的研究缺乏地基气溶胶激光雷达同步综合探空（水汽、气溶胶和气象）和卫星的观测内容，也缺少ATAL本身与高空卷云间的差别与联系的第一手地基观测数据。本项目拟用气溶胶激光雷达(含偏振观测)、COBALD探空仪（测气溶胶、高空卷云粒子在455 和940nm后向散射系数）在高原开展ATAL、高空卷云观测，并依托已有项目的水汽、臭氧及气象探空观测综合研究ATAL、高空卷云的垂直分布、变化特征及形成机理。本项目也为研究高原地区STE中气溶胶的天气、气候效应及卫星气溶胶和卷云产品的适用性提供基础。

A maximum concentration of aerosols in the upper troposphere and lower stratosphere (UT-LS, about 13-18 km above sea surface level) is located in the anticyclone center of Asian summer monsoon circulation, which is called as The Asian Tropopause Aerosol Layer (ATAL). The studies by model simulation and satellite observation speculated that ATAL has a closely connection with water vapor vertical transportation, gas-to-particle conversion process from aerosol precursors, formation and disappearing of cirrus and followed by radiative forcing. However, the detailed study on ATAL has been limited by the lack of simultaneous and cooperative measurement with the ground based lidar and radiosonde (water vapor, aerosol and meteorological parameters) as well as satellite, especially for the observation data from cirrus near ATAL. In this study we intend to employ lidar (with polarization measurement) and COBALD (measuring aerosol and cirrus at 455nm (blue) and 940nm (infrared) wavelength) to observe ATAL and cirrus over Tibetan Plateau. Together with water vapor, ozone and meteorological parameters from an underway project, we expect that the detailed vertical distribution and evolution characteristics as well as the formation mechanism of ATAL and cirrus can be obtained. Additionally, aerosol and cirrus products from satellite will be validated by our observations. These studies also aim to be the basis of further study on the influence of ATAL on weather and climate.